Prawn is a common name for small aquatic crustaceans with an exoskeleton and ten legs (i.e. a member of the order decapoda), some of which can be eaten.The term prawn is used particularly in the United Kingdom, Ireland, and Commonwealth nations, for large swimming crustaceans or shrimp, especially those with commercial significance in the fishing industry. Shrimp that fall in this category often belong to the suborder Dendrobranchiata.
The fish which is allowed to eat must have scales on it and must die out of the water and not in the water.
Prawns are allowed to eat.
Crabs and all other water animal are not Halal to eat.
The reason of all rules of Islam is based on getting the benefit and avoiding the harm. Allah (SWT) knows the secrets and real effects , and He ordered us to avoid things which are Haraam, and we believe that He does not prevent us from any thing for no reason, but for His absolute wisdom, whether we know it or not.
Crab, lobster and other sea and water animals except prawns are Haraam. Simply because they ( except prawns) are harmful for our health and He knows the details of the harm. We do trust His absolute wisdom and never argue with Him. Scientific researches are improving day by day and providing more evidence that every Haraam in Islam is in fact harmful. We need to submit to the Will of Allah (SWT) with surety that all His orders to us are to protect us from harm and provide us with benefits.
Thank you for your question. Prawns are halal. Below is a quote from the book Jurisprudence made Easy by Ayatullah Sistani:
Among marine animals and amphibians that are haraam to eat are cat fish, tortoise, frog, and lobster.
* What about prawns?
- They are halal to eat, for scales cover their skin.
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